The present invention relates to an encoded symbol reader used to decode encoded symbols such as two dimensional tessellated codes.
Recently, point-of-sale systems have employed encoded symbol readers in order to scan bar-code labels on products to increase the speed at which products can be processed through a check-out line of a store. However, bar-code labels store data in only one direction (i.e., the scanning direction) and therefore can only store a limited amount of data.
To overcome the problem of limited data storage, a new type of symbol which stores data in two directions has been proposed. This new type of symbol (hereinafter referred to as a two-dimensional symbol) uses a tessellated pattern to store the data.
However, the two-dimensional symbol may be read in a orientation other than its proper orientation. For instance, the symbol code may be upside down or left/right reversed. Conventionally, in the case of reading a left/right reversed image, the encoded symbol is read and the data corresponding to the read image is stored in a memory. Then, in order to decode the data, the stored image data is read out of the memory in a reverse order and stored in another memory as reversed image data. Then the reversed image data is decoded.
However, in a conventional encoded symbol reader having a conventional reading device such as a CCD, the amount of data corresponding to the read image may be large (i.e., 500.times.500 pixels). Therefore, the process of reading the image data out in reverse order, storing the read out image data in another memory, and then decoding this reversed image data is very slow and inefficient.
Further, the conventional encoded symbol reader requires an operator to input the orientation of the encoded symbol relative to the encoded symbol reader.